SINGAPORE - Thursday's floods were the result of the unfortunate coming together of two forces of nature - heavy rain and high tide.
The rain was particularly heavy as a result of "the convergence of winds over the region", according to the National Environment Agency.
It fell heaviest near Kent Ridge, reaching 102.8mm in just over an hour. The nearby Sungei Pandan Kechil canal was supposed to direct the rainfall out to sea, but it was already filling up fast because of the high tide.
The ensuing lack of drainage led to flood waters rising to a height of half a metre across 90m of the Ayer Rajah Expressway (AYE), where all four lanes leading to the city were closed for about 40 minutes.
National water agency PUB's chief engineer of drainage planning, Mr Ridzuan Ismail, said on Thursday that the canal was due for an upgrading and that a preliminary study had already been done.
It had overflowed before. In 2011, the flooding led to the basement carpark of Varsity Park Condominium along West Coast Road becoming inundated, leaving cars in bumper-high water.
Then in February this year, intense rain in the area led to the closure of one lane of the AYE.
Yet upgrading of the canal in this problematic area will not happen immediately. Mr Ridzuan said that it will take a further nine months to determine the scope of works needed, including how much the canal's capacity can be expanded and what construction method to use.